The Lettuce Sea Slug (Elysia crispata) is one of the most ornate sea slugs found in the Caribbean. The pictured specimen here was seen merrily grazing away on algae covered rocks without a care in the world. They are actually far more common than one thinks, with their fabulous ruffles acting as very effective camouflage. These ruffles are used to increase their bodies surface area, through which they absorb oxygen, thus they are essentially a rudimentary type of lung. I have to say though, I get the impression they think of them more as a fashion statement.
The sea slugs belong to the class Gastropoda, subclass Ophisthobranchia, which they share with other shell-less snails such as the sea hares and nudibranchs. Of particular interest is that the sea slugs have a sac in their alimentary canal that collects discarded teeth. I guess they are saving up to one day make a trip to the tooth fairy and boost their retirement fund. Clever move.
Originally posted on Instagram @sea_anguilla with the text: Lettuce Sea Slug browsing the rocks for breakfast. This ruffled beauty is not particularly common in Anguilla, although it’s camouflage makes it difficult to spot. Worth looking out for though as its slow moving nature means it is relatively easy to photograph.